Safety arrangement for fuses for nonspinning projectiles, more particularly rocket projectiles

ABSTRACT

A safety apparatus for projectile fuses which includes a primer carrying swing slide and an inertia weight. A stop sleeve surrounds and cooperates with the inertia weight to control its movement, with the controlled movement of the inertia weight in turn controlling the movement of the swing slide from a safe to an armed position.

United States Patent [51] [50] Field of 102/78, 76, 82, 83, 84, 70

[72] Inventor JosefMuller Schramberg-Sulgen/Wurttemberg, Germany 35,654

[21] Appl. No. [22] Filed [56] References Cited UNITED STATES PATENTS 2/1960 Von Nemeth 3/1964 Kaiser et a1.

May 8,1970 [45] Patented Nov. 9,1971

3,157,125 11/1964 Lohmann......

3,495,533 2/1970 Muller..........................

Primary Examiner-Samuel W. Engle Attorney-Burns, Doane, Benedict, Swecker & Mathis ABSTRACT: A safety apparatus for projectile fuses which in- [73] Assignee Gebruder J unghans G.m.b.H.

Schramberg/Wurttemberg, Germany [32] Priority May 10, 1969 [3 3 Germany [54] SAFETY ARRANGEMENT FOR FUSES FOR NONSPINNING PROJECTILES, MORE cludes a primer carrying swing slide and an inertia weight. A

PARTICULARLY ROCKET PROJECTILES 7 Claims, 7 Drawing Figs.

stop sleeve surrounds and cooperates with the inertia weight to control its movement, with the controlled movement of the inertia weight in turn controlling the: movement of the swing slide from a safe to an armed position.

PATENTEU NOV 9 I971 SHEET 5 UF 6 SAFETY ARRANGEMENT FOR FUSES FOR NONSPINNING PROJECTILES, MORE PARTICULARLY ROCKET PROJECTILES The invention relates to a safety arrangement for fuses for nonspinning projectiles, more particularly projectiles having a low acceleration such as rocket projectiles. The arrangement includes a swing slide carrying a primer pellet. A nonrotatable inertia weight is in engagement with the said slide. In the safe state, a stop element is associated with the slide and this element is changed to a nonsafe position on acceleration of the projectile by means of a release weight.

The fuse can be provided with percussion or time ignition. Preferable it is intended for booster use.

In an older construction of such a safety arrangement an inertia weight, engaged with a swing slide carrying the primer pellet is in turn engaged by a stop lever controlled by the release weight.

It has now been found by experiment that in the older construction, damage occurred between the stop lever and the inertia weight which prejudiced the reliable triggering of the fuse.

The invention has as its object to obviate this disadvantage and to improve the operational ability of the fuse.

This is achieved according to the invention in that in a safety arrangement of the type initially indicated, the stop element consists of a stop sleeve which surrounds the inertia weight and is provided with longitudinal slots. The inertia weight bears on the stop sleeve by means of bearing fingers. After a rotational movement of the stop sleeve brought about by the release weight, the bearing fingers fall into the longitudinal slots thereof.

Preferably, the rotation of the stop sleeve is effected by a lever controlled by the release weight.

According to a further expedient feature of the invention, the bearing fingers are arranged on a disc secured nonrotatably on the inertia weight.

For reliable guiding, the inertia weight is guided on at least one guide pin, preferably on three guide pins offset by 120 relatively to one another.

In order to achieve an adequate delaying of the operation wherein the fuse becomes live, the inertia weight according to a further expedient feature of the invention is under the influence of an advancing spring and has a finger with which it engages in a meander-form recess of the swing slide carrying the primer pellet and subjected to the action of a torsion spring, the said recess merging into a front peripheral recess of the swing slide.

For further increasing the delay time, the inertia weight can engage with a pin into a coarse-pitch groove of a delay shaft, the rotation of which is checked by an escapement system.

Conveniently, the escapement system comprises a gearwheel secured on the shaft, an intermediate wheel, an escape wheel and a pawl device.

One preferred example of embodiment is illustrated in the drawings wherein:

FIG. 1 is a plan view on to the safety arrangement;

FIG. 2 shows a longitudinal section taken on the section line A-A of FIG. 1;

FIG. 3 shows a longitudinal section taken on the section line B-of FIG. 1;

FIG. 4 shows a perspective sectional view of the safety arrangement in the safe state;

FIG. 5 shows a perspective view of the safety arrangement in the safe state;

FIG. 6 shows a perspective view of the safety arrangement in an intermediate safe state;

FIG. 7 shows a perspective view of the safety arrangement in its released, or armed, state.

Of the fuse housing only the rear portion 10 is illustrated, in which the detonator 11, a propagation charge 12, the primer pellet swing slide 13 with the primer pellet 13a, and the other parts of the safety arrangement are arranged.

The primer pellet swing slide 13 is subjected to the force of a torsion spring 14. It is provided at its periphery with a meander-form recess 13b which merges into a front peripheral recess 13c, as FIG. 7 shows most clearly. In the recess 13b there is engaged a stop finger 18a which is arranged at a finger disc 18. Disc 18 is secured, for example by means of screws 17, on an inertia weight 16. Weight 16 is under the pressure of an advancing spring 15. The stop finger 18a could also be integral with the inertia weight 16.

Also arranged at the finger disc 181 are bearing fingers 18b which could also be integral with the inertia weight 16.

For guiding the inertia weight 16 there are used guide pins 19 which are arranged offset by relatively to one another.

The inertia weight 16 is surrounded by a stop sleeve 20 on the front end of which the stop finger 18a and the bearing fingers 18b bear when the fuse is at safe. The stop sleeve 20 is provided with longitudinal slots 20a in which the fingers 18a and 18b can fall after appropriate rotational movement of the stop sleeve 20. In an additional longitudinal slot 20b of the stop sleeve 20 there is engaged one arm of a two-arm release lever 21 which is pivotally mounted on a screw 22. The other arm of lever 21 abuts under the pressure of a spring 210, acting in the counterclockwise direction as shown in FIG. 1, on a release weight 23. Weight 23 is provided with a forwardly and outwardly extending cone and is under the pressure of an advancing spring 23a.

Concentrically with the inertia weight 16, which is provided with an appropriate bore, is a delay shaft 24. Shaft 24 has a coarse-pitch helical groove 24a in which is engaged a pin 16a of the inertia weight 16. The delay shaft 24 is under the action of an escapement system which comprises a gearwheel 25 secured on the said shaft so as to be nonrotatable relatively thereto, an intermediate gearwheel 26 meshed with wheel 25, an escape wheel 27 having a gear portion meshed with wheel 26, and a pawl device 28.

The safety arrangement operates as follows.

As shown in FIG. 5, before projectile acceleration, the apparatus is in a safe state.

On acceleration of the projectile, the release weight 23 moves to the rear as shown in FIG. 6, overcoming the force of its advancing spring 23a. The release lever 21 slides along the cone of the release weight 23 and in so doing is pivoted in the clockwise direction in opposition to the force of its spring 21a. In response to this pivoting movement of the release lever 21 and its arm engaged in a slot 20b, the :stop sleeve 21) is rotated so far that the bearing fingers 18b and the stop finger 18a can fall into the longitudinal slots 20a associated therewith in the stop sleeve 20, and the inertia weight 16 can withdraw, relative to the stop sleeve 20 and delay shaft 24. The rotational movement of the delay shaft caused by the interaction of pin 16a and helical groove 24a, and which is under the influence of the escapement system 25, 26, 27, 28, is slowed down and the relative moving-back or withdrawal of the inertia weight 16 is slowed down correspondingly.

At the end of the relative moving-back of the inertia weight 16, the stop finger 18a enters the rear portion, extending in the peripheral direction of the swing slide 13 carrying the primer pellet, of the meander-form recess 13b, so that the swing slide 13 can carry out a partial rotational movement under the action of the torsion spring 14 in such a manner that the stop finger 18a is situated in the right-hand portion of the recess 1312, which recess is seen in FIG. 7.

After the end of the acceleration period of the projectile, the inertia weight 16 is pressed forwards again by its advancing spring 15. The stop finger 18a slides forwards in the righthand portion of the meander-form recess 13!], being situated, towards the end of its advancing movement, in the recess 13c extending in the peripheral direction, whereupon a further rotational movement of the swing slide 13 carrying the primer pellet occurs into its armed position, as shown in FIG. 7.

The inertia weight 16 is under the influence of the escapement system during its advancing movement also.

I claim:

1. A safety apparatus for fuses, said apparatus comprising:

a swing slide carrying a primer pellet;

a nonrotatable inertia weight which is in rotation controlling engagement with said slide;

a stop sleeve which is provided with longitudinal slots and which generally surrounds the inertia weight;

bearing means carried by said inertia weight and operable in one rotational position of said stop sleeve to prevent axial movement of said inertia weight relative to said stop sleeve;

acceleration responsive release means operable to rotate said stop sleeve;

said rotation of said stop sleeve being operable to position said bearing means in said slots and permit axial movement of said inertia weight relative to said stop sleeve; and

engaging means interconnecting said inertia weight and said swing slide and operable in response to reciprocating movement of said inertia weight relative to said slide to permit fuse arming rotation of said swing slide.

2. A safety apparatus according to claim 1, wherein said acceleration responsive means includes:

a release lever engaging said stop sleeve; and

a release weight operable to rotate said lever in response to acceleration of said projectile, with rotation of said lever being operable to rotate said sleeve.

3. A safety apparatus according to claim 2 wherein said bearing means include bearing fingers arranged on a disc, with said disc being nonrotatably secured on the inertia weight.

4. A safety apparatus according to claim 3 including a plurality of guide pins operable to prevent rotation of said inertia weight and guide the reciprocating movement thereof relative to said sleeve.

5. A safety apparatus according to claim 4 including:

an advancing spring biasing said inertia weight generally toward said sleeve; said engaging means including a stop finger carried by said disc,

a meander-form recess carried by said slide and within which said stop finger is slidably positioned,

a torsion spring rotatably biasing said slide,

a front peripheral recess carried by said slide and operable to receive said finger from said meander-form recess in response to partial rotation of said slide, with said peripheral recess, when receiving said finger, being operable to permit rotation of said slide under the biasing influence of said torsion spring, to a fuse arming position, and

said meander-form recess, when receiving said finger being operable to permit said partial rotation of said slide under the biasing influence of said torsion spring and in response to said reciprocating movement of said inertia weight relative to said sleeve.

6. A safety apparatus according to claim 5 including impedance means comprising:

a pin carried by said inertia weight; a coarse-pitch helical groove carried by a delay shaft; and an escapement system connected with said delay shaft. 7. A safety apparatus according to claim 6 wherein said escapement system comprises a gearwheel which is secured nonrotatably on said delay shaft; an intermediate gearwheel meshed with said gearwheel; an escapement wheel including a gear portion meshed with said intermediate gearwheel; and a pawl cooperating with said escapement wheel to produce escapement controlled rotation of said gearwheel. 

1. A safety apparatus for fuses, said apparatus comprising: a swing slide carrying a primer pellet; a nonrotatable inertia weight which is in rotation controlling engagement with said slide; a stop sleeve which is provided with longitudinal slots and which generally surrounds the inertia weight; bearing means carried by said inertia weight and operable in one rotational position of said stop sleeve to prevent axial movement of said inertia weight relative to said stop sleeve; acceleration responsive release means operable to rotate said stop sleeve; said rotation of said stop sleeve being operable to position said bearing means in said slots and permit axial movement of said inertia weight relative to said stop sleeve; and engaging means interconnecting said inertia weight and said swing slide and operable in response to reciprocating movement of said inertia weight relative to said slide to permit fuse arming rotation of said swing slide.
 2. A safety apparatus according to claim 1, wherein said acceleration responsive means includes: a release lever engaging said stop sleeve; and a release weight operable to rotate said lever in response to acceleration of said projectile, with rotation of said lever being operable to rotate said sleeve.
 3. A safety apparatus according to claim 2 wherein said bearing means include bearing fingers arranged on a disc, with said disc being nonrotatably secured on the inertia weight.
 4. A safety apparatus according to claim 3 including a plurality of guide pins operable to prevent rotation of said inertia weight and guide the reciprocating movement thereof relative to said sleeve.
 5. A safety apparatus according to claim 4 including: an advancing spring biasing said inertia weight generally toward said sleeve; said engaging means including a stop finger carried by said disc, a meander-form recess carried by said slide and within which said stop finger is slidably positioned, a torsion spring rotatably biasing said slide, a front peripheral recess carried by said slide and operable to receive said finger from said meander-form recess in response to partial rotation of said slide, with said peripheral recess, when receiving said finger, being operable to permit rotation of said slide under the biasing influence of said torsion spring, to a fuse arming position, and said meander-form recess, when receiving said finger being operable to permit said partial rotation of said slide under the biasing influence of said torsion spring and in response to said reciprocating movement of said inertia weight relative to said sleeve.
 6. A safety apparatus according to claim 5 including impedance means comprising: a pin carried by said inertia weight; a coarse-pitch helical groove carried by a delay shaft; and an escapement system Connected with said delay shaft.
 7. A safety apparatus according to claim 6 wherein said escapement system comprises a gearwheel which is secured nonrotatably on said delay shaft; an intermediate gearwheel meshed with said gearwheel; an escapement wheel including a gear portion meshed with said intermediate gearwheel; and a pawl cooperating with said escapement wheel to produce escapement controlled rotation of said gearwheel. 